Maybe pregnant??

So I had during ovulation a week ago today. I know that this is so early, but I'm just so antsy about it and want to know my chances? My partner and I do smoke a lot (but I definitely plan to quit if I'm pregnant, of course)...so I know that it cuts the chances more low. But with that being said, is this worth getting excited about? What are the earliest symptoms that would occur? And is it worth trying a home pregnancy test earlier than your missed period?